(a) Field of the Invention
The present invention relates to glass cutting tools for scoring to-be-cut glass. More particularly it relates to that type of glass cutting apparatus which is held in the hand of a user and passed across a to-be-cut sheet or plate of glass to form a scoreline at which the glass is to be broken.
(b) Discussion of the Prior Art
Tools which are passed across a to-be-cut sheet or plate of glass to form a scoreline at which the glass is to be broken are usually referred to as "glass cutters" or "glass cutting apparatus." Hand held glass cutters are ordinarily comprised of an elongated body portion, which is held in the palm of the hand and guided by the thumb and forefinger, a glass scoring element which is secured to one end of the handle. The glass scoring element most often includes a cutting element which may be in the form of either a rotatable element, such as a steel wheel, or a hard element, such as a diamond. In the use of such a device to score a glass sheet which is to be broken to a predetermined size or shape, the glass scoring element portion of the glass cutting apparatus is usually held firmly against the to-be-cut glass and drawn towards the user. In order to effect accurate cutting of glass with such a type of cutter, it is essential that the glass cutting apparatus not only be maintained in firm engagement with the glass during the entire cutting operation, but also that the glass scoring element be held substantially perpendicular with respect to the glass sheet. This requires that the user maintain a firm, to strong, grip, on the glass cutting apparatus and hold his or her wrist in a rotated position in order to maintain the substantially perpendicular relationship between the glass scoring element and the glass. It also requires that the glass cutting apparatus be drawn or pulled along the surface of the glass toward the user, which in turn, requires that the user's hand and wrist be turned inwardly, in an unnatural position, putting stress upon the hand and wrist. If this is not done, using current glass cutters, the glass may not be scored accurately, and, after being broken may require grinding, if too large, or non-use or destruction if too small.